Mallinckrodt Professor of Physics and Professor of the History of Science, Emeritus, Harvard University; Author, Einstein for the 21st Century: His Legacy in Science, Art, and Modern Culture

Mallinckrodt Research Professor of Physics and Research Professor of History of Science, Harvard University; Author, Thematic Origins of Scientific Thought

The Increasing Coalescence of Scientific Disciplines

Under our very eyes, research in science has been taking a courageous and promising turn, to realize in our time an ancient dream.

Since Thales and other philosophers on the island in the Ionian Sea, over 2500 years ago, there has been an undying hope that under all the diverse and fluctuating phenomena, there could be found in Nature a grand, majestic order. This fascination, the "Ionian Enchantment," persisted ever since in various forms.

Thus, Isaac Newton thought mechanical forces that explained the motions of the solar system would also turn out to run all else, including human senses. After Darwin's magnificent synthesis, many attempts were made to extend it to include all societal phenomena. The influential Austrian polymath, Ernst Mach, to whom young Einstein referred as one of his most important influences, taught that the true task of scientific research is to establish a form of fundamental science, an Einheitswissenschaft, on which is based every different specialty. From about 1910 on, an increasing number of scientists in Europe and America gave allegiance to the idea of the "Unity of Science," a widespread movement hoping to find functioning bridges between not only different sciences but also between science and philosophy—Niels Bohr being one of the prominent promoters.

But, by and by, it became clear that such hopes were at best premature, that there was not enough of what William James had called "cash value," in terms of having secured many actual accomplishments—not least in attaining a Unified Field Theory. At one of the last meetings devoted to discussions about the Unity of Science, in 1956, J. Robert Oppenheimer, with typical eloquence, offered a valedictory to the Ionian Enchantment, with these words:

"It may be a question [whether there] is one way of bringing a wider unity in our time. That unity, I think, can only be based on a rather different kind of structure than the one most of us have in mind....The unity we can seek lies really in two things. One is that the knowledge that comes to us in such terrifyingly inhumanly rapid rate has some order in it....The second is simply this: We can have each other to dinner. We ourselves, and with each other by our converse, can create, not an architecture of global scope,but an immense, intricate network of intimacy, illumination, and understanding."

But even as such opinions were accepted with resignation, something new had been born, quietly grew, and in our time has become the source of increasing optimism about the value of the old dream—by turning in a new direction. I mean that scientific research, at first only sporadically during the last century, but more and more in our time, has been successfully reaching out for a new sort of unity—in practice, for an integration among disciplinary fragments. This time the movement is not driven by a philosophy of science or a search for the Ur-science. Rather it is appearing as if spontaneously in the pursuit and progress of research science itself.

There is an increasing coalescence of scientific disciplines in many areas. Thus the discovery of the structure of the genome not only required contributions from parts of biology, physics, chemistry, mathematics, and information technology, but in turn it led to further advances in biology, physics, chemistry, technology, medicine, ecology, and even ethics. And all this scientific advance is leading, as it should, to the hopeful betterment of the human condition (as had been also one of the platform promises of the Unity of Science movement, especially in its branch in the Vienna Circle).

Similar developments happen in the physical sciences—a coalescence of particle physics and large-scale astronomy, of physics and biology, and so forth. It is a telling and not merely parochial indicator that about half of my 45 colleagues in my Physics Department, owning to their widespread research interests, now have joint appointments with other departments at the University: with Molecular and Cellular Biology, with Mathematics, with Chemistry, with Applied Sciences and Engineering, with History of Science. Just now, a new building is being erected next to our Physics Department. It has the acronym LISE, which stands for the remarkable name, Laboratory of Integrated Science and Engineering. Although in industry, here and there, equivalent labs have existed for years, the most fervent follower of the Unity of Science movement would not have hoped then for such an indicator of the promise of interdisciplinarity. But as the new saying goes, most of the easy problems have been solved, and the hard ones need to be tackled by a consortium of different competences.

From other parts of this university, plans are under way to set up a program for higher degrees in the new field of Systems Biology, which has the goal of reaching "an integrated understanding" of biological/medical processes; that program is to bring together faculty and students from biology, medicine, chemistry, physics, mathematics, computation and engineering. And these parochial examples are indications of a general trend in many universities. The new password to success is now "integration" and "interdisciplinarity." If an "official" sacralization of this movement were needed, it would be the 2005 release of a big volume by the National Academy of Sciences, with the title "Facilitating Interdisciplinary Research."

All this is not precisely what the philosophers and scientists, from Thales on, were hoping for. We will not, at least not for a long time, have that grand coalescence of all sciences and more. What has come lacks exalted philosophical pretensions, being instead a turn to weeks and years of many-heads-together, hands-on work on specific, hard problems of intense scientific interest, many of them also of value to society at large.

And, of course, these co-workers can also still have each other to dinner.